CN-122013022-A - Non-oriented silicon steel and manufacturing method thereof

CN122013022ACN 122013022 ACN122013022 ACN 122013022ACN-122013022-A

Abstract

The invention belongs to the technical field of metallurgical engineering, and particularly relates to non-oriented silicon steel and a manufacturing method thereof, wherein the non-oriented silicon steel comprises the chemical components of less than or equal to 0.003 percent of C, 3.2 to 3.5 percent of Si, 0.4 to 0.6 percent of Mn, 0.5 to 0.8 percent of Als, 0.03 to 0.05 percent of Sn, less than or equal to 0.005 percent of S, less than or equal to 0.005 percent of N, less than or equal to 0.005 percent of Ti, and the balance of Fe and unavoidable impurities, and the production process comprises the steps of regulating and controlling recrystallization texture by controlling alloy components and matching with the segregation of Sn element, improving the electromagnetic performance of a finished product, regulating and controlling the recrystallization proportion of a finished product tissue by optimizing a normalizing and annealing process, and improving the mechanical property of the finished product. The process flow is relatively short, the mechanical property and the electromagnetic property are well represented, excessive solid solution strengthening elements Ni, cr and other noble metals are not needed to be added, the cost is low, and the method is suitable for manufacturing the high-rotation-speed rotor core of the new energy driving motor.

Inventors

XU WENXIANG
CHEN MINGXIA
SHI LIFA
LU TIANLIN
CHENG GUOQING
XIA XUELAN
LIU QINGSONG
QI XUAN
ZHAN YUNGAO
Ding Shineng

Assignees

马鞍山钢铁有限公司

Dates

Publication Date: 20260512
Application Date: 20260227

Claims (7)

1. The manufacturing method of the non-oriented silicon steel is characterized by comprising the following steps of: S1, decarburizing, desulfurizing and adding alloy raw materials in the steelmaking process to ensure that the chemical components of the steel billet are less than or equal to 0.003 percent, 3.2 to 3.5 percent of Si, 0.4 to 0.6 percent of Mn, 0.5 to 0.8 percent of Als, 0.03 to 0.05 percent of Sn, less than or equal to 0.005 percent of S, less than or equal to 0.005 percent of N, less than or equal to 0.005 percent of Ti, and the balance of Fe and unavoidable impurities in percentage by weight; S2, continuously casting molten steel into a slab, heating the slab in a heating furnace, carrying out 7-pass hot rolling on the slab to a hot rolled slab with the thickness of 2.0-2.3mm, controlling the final rolling temperature at 850-870 ℃, cooling to 600-650 ℃, and coiling; S3, heating the coiled strip steel in a normalizing furnace to control the normalizing temperature to be 830-870 ℃ for 2-4min, cooling, pickling, and carrying out 5-6 times of cold rolling to reach the target thickness; S4, continuously annealing the cold-rolled sheet, wherein the annealing temperature is controlled to be 650-710 ℃, and the heat preservation time is controlled to be 60-120 seconds; S5, coating the annealed plate with an insulating coating through a coating roller after alkali washing, curing the insulating coating at 380-650 ℃, and cooling after curing to finish the manufacture of the non-oriented silicon steel.
2. The method for producing non-oriented silicon steel according to claim 1, wherein the temperature of the heating furnace is controlled to 1100-1250 ℃, and the heating and heat-preserving time is not less than 210min.
3. The method for producing non-oriented silicon steel according to claim 2, wherein the normalized steel is cooled to 600-700 ℃ at 5-10 ℃ per second and then cooled to below 100 ℃ at 20-50 ℃ per second.
4. A method for producing non-oriented silicon steel according to claim 3, wherein the pickling is performed with 45-65% hydrochloric acid at a pickling temperature of 60-85 ℃.
5. The method of claim 4, wherein the continuous annealing is performed in a protective atmosphere of 3:7 by volume of H 2 and N 2 .
6. The method for manufacturing non-oriented silicon steel according to claim 5, wherein a laminar cooling mode is adopted before coiling, and the temperature during coiling is ensured to be within a set range through sectional cooling.
7. A non-oriented silicon steel manufactured by the manufacturing method of the non-oriented silicon steel, wherein the chemical components of the non-oriented silicon steel are, by weight, less than or equal to 0.003% of C, 3.2-3.5% of Si, 0.4-0.6% of Mn, 0.5-0.8% of Als, 0.03-0.05% of Sn, less than or equal to 0.005% of S, less than or equal to 0.005% of N, less than or equal to 0.005% of Ti, and the balance of Fe and unavoidable impurities.

Description

Non-oriented silicon steel and manufacturing method thereof Technical Field The invention belongs to the technical field of metallurgical engineering, and discloses non-oriented silicon steel and a manufacturing method thereof. Background The non-oriented silicon steel is mainly applied to various generators, motors and rotating equipment, is a main raw material for motor production, and is also an indispensable soft magnetic material in the fields of electronics, motors, military industry and the like. In recent years, along with the tightening of national energy policies, industrial motors, compressors and new energy driving motors have higher requirements on electromagnetic performance and mechanical performance of non-oriented silicon steel. Especially, along with the acceleration of the transition speed from the traditional fuel car to the new energy car in the domestic car industry, the demand for the non-oriented silicon steel for the driving motor is gradually increased. Meanwhile, higher requirements are put forward on the electromagnetic performance and mechanical performance of silicon steel, and for a rotor iron core, the rotor can bear extremely large centrifugal force due to high rotating speed, and the rotating speed of a part of new energy driving motors in China at present reaches 22000 revolutions per minute, even 30000 revolutions per minute. The intensity of the silicon steel for the mainstream new energy driving motor is generally 500-600Mpa, which can not meet the requirement of the current driving motor for high speed. The main stream strengthening means at present comprises solid solution strengthening, precipitation strengthening and other modes; Chinese patent CN114657461 a discloses a high-strength non-oriented silicon steel based on solid solution strengthening and a method for preparing the same, which performs solid solution strengthening by adding Si and P elements and performs dislocation strengthening by low temperature annealing. The chemical composition of the non-oriented silicon steel is 2.8-4.8 wt.% of Si, 0-0.2 wt.% of P, 0-0.5 wt.% of Mn, 0-0.5 wt.% of Al, less than or equal to 100ppm of (C+N+O+S) and the balance of Fe. The preparation method comprises vacuum smelting, casting forging, hot rolling processing and normalizing heat treatment, or thin strip continuous casting. The strength of the finally prepared high-strength non-oriented silicon steel Rm is 620-750 MPa, and the strength of the non-oriented silicon produced by the scheme can only reach about 750MPa at most, and is relatively low. Chinese patent CN 120591677A discloses a high-strength non-oriented silicon steel with yield strength of 930MPa and its production method, and the patent uses three strengthening modes of dislocation strengthening, solid solution strengthening and precipitation strengthening. The chemical components of the non-oriented silicon steel are ：Si：3.0-4.0％、Al：0.1-.2％、Mn：0.1-1.0％、Nb:0.0005-0.0010％、Ti:0.001-0.0030％、V:0.0010-0.0025％、C:0.0020-0.0035％、N:0.0010-0.0025％,, and the chemical components of Si+Al+Mn are 4.0-5.4%, nb+Ti+V are 0.0045-0.0055%, C+N is 0.0035-0.0050%. The production method adopts the process route of converter smelting, RH refining, continuous casting, hot rolling, pickling, cold rolling, annealing and coating, and obtains the excellent performances of yield strength Rp0.2 more than or equal to 930MPa, iron loss P1.0/400 less than or equal to 57W/kg and magnetic polarization strength J5000 more than or equal to 1.52T through the hot rolling process of designing the matching relation of composition, annealing temperature and annealing speed, high-temperature long-time heating, low-temperature final rolling and high-temperature coiling. The high-strength non-oriented silicon steel manufactured by the scheme has very excellent mechanical properties, but the electromagnetic properties, particularly the magnetic polarization strength, of the high-strength non-oriented silicon steel are relatively low, and when the iron core rotor works, the rotor tooth part or the yoke part can possibly enter a magnetic saturation state in advance, so that the efficiency is influenced. Japanese patent JP 2011-184787 discloses a production method of high-strength unoriented silicon steel, which comprises the following chemical components of 0.003% of C, 3% of Si, 0.75% of Al, 0.24-2.18% of Mn, 2.59% of Ni, 2.09-6.14% of Cr, 0.03% of P, 750 ℃ multiplied by 20s of annealing process, 0.2mm of finished product thickness, 609-679MPa of Re, 712-776MPa of Rm, 29-31% of A, 4.3-4.5W/kg of P, 10/1000:38-44W/kg of P and 1.58-1.65T of B. Japanese patent JP 2008-261053 discloses a method for producing Cu-containing high-strength unoriented silicon steel. The chemical components of the alloy are C <0.003%, si 1.1-1.3%, al 0.005%, mn 0.13-0.44%, P0.015-0.021%, S <0.003% and Cu 0.93-2.24%. The casting blank thickness is 250mm, the soaking temperature is 1100 ℃, the hot rolled plate thickness is 2mm, the coi